A simple thing they can do is put a limit on their query. most of the time the performance hit is on the data stream and limiting the results can help a lot. Some tools like MySQL workbench have an implied limit.

E..gselect * from MACHINE LIMIT 1000

If you think he is locking it up then he is doing so as the R1 user. If you connect as the R1 user you can see your own processes with the command:SHOW FULL PROCESSLIST;

If hie statement is not "locked" but yours is (or the UI) is then his statement is the culprit.

If he needs help query writing he'll get more free help here then he from support as it is not the kbox that is broken in that case. If it's something that should work but should have an index or is a mysql bug then we can spot it and send him on to support.